In drawing FIG. 1, reference characters 10-17, "L", and "W" thereof adequately describe a rudimentary prior art flotation sleeping mattress adapted to be inflated by water or air flotation fluid. Such prior art flotation mattress comprises a fluid-inflatable shell 10 defined by six substantially rectangular flexible fluid-impervious panels 11-16 (e.g. thermoplastic vinyl resinous sheeting) and at least one panel (e.g. top-panel 11) being provided with a spout means therethrough (e.g. tubular spout 17 for permitting the introduction/evacuation of filling water).
Of the six rectangular panels 11-16 defining six-sided shell 10, two are horizontal broad-panels including a top-panel 11 overlying a dimensionally similar bottom-panel 12 and both having four lineal edges including:
a pair of substantially parallel lengthier longitudinal-edges (e.g. 11A-11B, 12A-12B) defining therebetween a finite lateral-width "W" for the top-panel 11 and for the bottom-panel 12; and
a pair of substantially parallel shorter lateral-edges (e.g. 11M-11N, 12M-12N) defining therebetween a finite longitudinal-length "L" for top-panel 11 and for bottom-panel 12.
Six-sided shell 10 also includes two dimensionally similar and longitudinally extending uprightable side-panels 13 and 14 and each having continuous water-impervious connections of said finite longitudinal-length "L" along respective lineal edges of the broad-panels (e.g. side-panel 13 along edges 11A and 12A, and side-panel 14 along edges 11B and 12B). Finally, six-sided shell 10 includes two dimensionally similar and laterally extending uprightable end-panels 15 and 16 and each having continuous fluid-impervious connections of said finite lateral-width "W" along respective lineal edges of the broad-panels (e.g. end-panel 15 along edges 11M and 12M, and end-panel 16 along edges 11N and 12N). Thus, for example, the shell 10 might be filled with water, such as through the cappable (e.g. 18) tubular spout 17, to provide an operational rudimentary flotation sleeping mattress.
The prior art flotation sleeping mattress as described in the two immediately preceeding paragraphs exhibits the undesireable phenomenon of occupant induced abrupt fluid displacements. In the case of water filled mattresses, this phenomenon is exhibited as undulating water waves that are particularly objectionable in the lateral direction. In the case of air inflated mattresses, the phenomenon is exhibited as objectionable bulging. And in the water inflated mode, there is the problem of purging air bubbles from the water flotation medium.